Synthesis of 4-ketocyclopentene and cyclopentadiene compounds

ABSTRACT

A process for forming 4-ketocyclopentene and substituted 4-ketocyclopentene compounds starting from the corresponding 1-carbohydrocarbyloxy-2-keto-4-hydroxy-5-cyclopentene by reduction followed by decarboxylation using zinc dichloride or zinc dibromide. The ketone may thereafter be converted to a cyclopentadiene compound by reducing the ketone to form an alcohol, replacing the hydroxyl functionality of the alcohol under substitution conditions with a leaving group, and deprotonating the resulting product under base induced elimination conditions to form the cyclopentadiene compound. Alternatively functionalized cyclopentadienyl compounds can be produced without isolation of an unsubstituted cyclopentadienyl compound by combining the elimination and deprotonation steps with a replacement step in a single unit operation.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of U.S. applicationSer. No. 09/443,394, filed Nov. 19, 1999, which claims benefit ofpriority from provisional application 60/122,614, filed Mar. 3, 1999.

FIELD OF THE INVENTION

[0002] This invention relates to the synthesis of 4-ketocyclopentenecompounds including further substituted derivatives thereof, and theirconversion to cyclopentadiene compounds or substituted cyclopentadienecompounds, which are useful chemicals, particularly in the synthesis ofcyclopentadienyl containing metal complexes useful in additionpolymerization catalyst compositions. Group 4 metal complexes containingthe foregoing cyclopentadienyl ligands are especially suited for use incatalyst compositions for the homopolymerization of ethylene orpropylene and the copolymerization of ethylene with an α-olefin. Thepresent process is particularly suitable for use in the industrial scalepreparation of 4-ketocyclopentene or substituted 4-ketocyclopentenecompounds, cyclopentadiene or substituted cyclopentadiene derivativesthereof, and in the synthesis of cyclopentadienyl or substitutedcyclopentadienyl containing metal complexes therefrom.

BACKGROUND

[0003] The preparation of cyclopentadiene compounds from variousstarting materials is well known. Metal complexes containingcyclopentadienyl or substituted cyclopentadienyl ligands are also wellknown. Several techniques for preparing such ligands are disclosed inU.S. Pat. Nos. 5,703,187, 4,985,576, 5,646,083, 5,597,935, andEP-A-563365. In copending application Ser. No. 8/122958, filed Jul. 27,1998, the preparation of certain 1H-cyclopenta(l)phenanthrene containingmetal complexes and their use in addition polymerization catalystcompositions is disclosed and claimed. The technique for preparing suchcomplexes disclosed by the reference started with1H-cyclopenta-(l)phenanthrene. In JACS, 78, 2547-2551 (1956), asynthetic scheme for preparing 1H-cyclopenta(l)phenanthrene, theultimate step involving dehydration of2,3-dihydro-2-oxo-1H-cyclopenta(l)phenanthrene with boric acid wasdisclosed. Disadvantageously, this particular procedure resulted in lowyields and insufficient purity of the resulting ligand group containingcompounds.

[0004] Previously known synthetic procedures involved multiple unitoperations, thereby making the process less efficient than desired.Accordingly, it would be desirable if there were provided a process forpreparing 4-ketocyclopentene or substituted 4-ketocyclopentene compoundsand cyclopentadiene or substituted cyclopentadiene derivatives thereofin higher yields and purity.

SUMMARY OF THE INVENTION

[0005] According to the present invention there is provided a processfor forming 4-ketocyclopentene and substituted 4-ketocyclopentenecompounds starting from the corresponding1-carbohydrocarbyloxy-2-keto-4-hydroxy-5-cyclopentene by reductionfollowed by decarboxylation. Preferably, the reduction is occasioned byreaction of the initial compound with a metal, preferably zinc. Thedecarboxylation is preferably conducted by further reaction of theintermediate with an inorganic halide compound and one or more organicacids under hydrolysis and condensation conditions. The reduction anddecarboxylation may be conducted simultaneously or sequentially in thesame reactor or in different reactors. Preferably the carboxylatecompound is contacted with zinc in the presence of a mixture of anorganic acid and hydrochloric acid, zinc dichloride or zinc dibromide.

[0006] The foregoing procedure is illustrated schematically as follows:

[0007] wherein, R is C₁₋₂₀ hydrocarbyl, preferably C₁₋₄ alkyl; and

[0008] R¹ independently each occurrence is hydrogen, hydrocarbyl, silyl,germyl, halide, or halo- substituted hydrocarbyl, said R¹ group havingup to 40 atoms not counting hydrogen atoms, and optionally two or moreof the foregoing adjacent R¹ groups may together form a divalentderivative thereby forming a saturated or unsaturated fused ring ormultiple ring system, and further optionally one or more of the carbonsof R¹ in any of the so formed rings may be replaced by a nitrogen,boron, phosphorus or sulfur atom.

[0009] Beneficially, the foregoing improved process incorporatesmultiple chemical transformations into a single step process therebysignificantly improving the efficiency of the preparation.

[0010] In a further embodiment of the present invention the resultingketone is converted to a cyclopententadiene or substitutedcyclopentadiene compound by a series of reactions which beneficially maybe performed sequentially in the same reactor or in multiple reactors.In the process the ketone is reduced to form an intermediate alcohol,the hydroxyl functionality is replaced under substitution conditionswith a leaving group or otherwise converted to a leaving group, and theresulting product is deprotonated under base induced eliminationconditions to form the cyclopentadiene compound. If desired, a suitablefunctional substituent may be incorporated simultaneously with theelimination step. This process is illustrated schematically as follows:

[0011] wherein R¹ is as previously defined, and

[0012] Lg is a suitable ligand group that is subject to base inducedelimination. Preferred Lg groups are: halo, silyl, OSO₂R⁶, —Si(R⁵)₂—,—Si(R⁵)₂N(R⁵)₂), or —Si(R⁵)₂N(R⁵)— groups, wherein R⁵ is a C₁₋₂₀aliphatic or cycloaliphatic group, and R⁶ is R⁵ or a C₆₋₂₀ aryl group orsulfonate ester such as tosyl or mesyl. Most preferably, Lg is halo,especially bromo.

[0013] When further cyclopentadienyl substituted compounds are desired,the final elimination step may be followed by further substitution of Lgwith a functional substituent or even formation of dimeric bridgedligands through a coupling of ligand groups, utilizing techniques wellknown to the skilled artisan. Highly preferred functional substituentsinclude metals, hydrocarbyl, silyl, hydrocarbyl- or polyhydrocarbyl-substituted silyl, silyl- or polysilyl- substituted hydrocarbyl groups,metallated derivatives of such hydrocarbyl, silyl, substituted silyl orsubsitituted hydrocarbyl groups, or bridging groups of the formula:-Z′Y- when a coupled product is formed, or masked, metallated, orcoupled derivatives thereof, said functional substituent having up to 50atoms not counting hydrogen, wherein:

[0014] Y is —O—, —S—, —NR⁵—, —PR⁵—; —NR⁵ ₂, —PR⁵ ₂, or

[0015] Z′ is SiR⁵ ₂, CR⁵ ₂, SiR⁵ ₂SiR⁵ ₂, CR⁵ ₂CR⁵ ₂, CR⁵═CR⁵, CR⁵ ₂SiR⁵₂, BR⁵, B═NR⁵ ₂, or GeR⁵ ₂; and

[0016] R⁵ each occurrence is independently hydrogen, or a memberselected from hydrocarbyl, hydrocarbyloxy, silyl, halogenated alkyl,halogenated aryl, and combinations thereof, said R⁵ having up to 20non-hydrogen atoms, and optionally, two R⁵ groups from Z′ (when R⁵ isnot hydrogen), or an R⁵ group from Z′ and an R⁵ group from Y form a ringsystem.

[0017] Masked derivatives of the foregoing ligands are those ligandscontaining an easily removable group at the position desired for latercoupling or further functionalization of the compound. An example is atrihydrocarbylsilyl group, especially trimethylsilyl. In a highlypreferred embodiment of the invention the foregoing Lg group is replacedwith the desired functional ligand group in a single step which is acombination of elimination, deprotonation and replacement operationsusing two equivalents of base for each equivalent of cyclopentedienecompound and the addition of the source for the functional group, R⁷Fs,where R⁷ is a leaving group, preferably halogen or a sulfonate ester,and Fs is a functional substituent, preferably -Z′YH. Because thecombination of three processes in one step does not involve dehydrationof an alcohol intermediate, formation of dimeric byproducts through aDiels-Alder reaction of the diene is avoided. This combined process maybe illustrated schematically as follows:

[0018] Finally according to the present invention there is provided aprocess for preparing metal complexes comprising cyclopentadienyl- orsubstituted cyclopentadienyl- ligands using one or all of the foregoingintermediate process steps. The present processes result in the highlyefficient production of metal complexes and metal complex intermediates.

DETAILED DESCRIPTION OF THE INVENTION

[0019] All reference to the Periodic Table of the Elements herein shallrefer to the Periodic Table of the Elements, published and copyrightedby CRC Press, Inc., 1995. Also, any reference to a Group or Groups shallbe to the Group or Groups as reflected in this Periodic Table of theElements using the IUPAC system for numbering groups. The term“hydrocarbyl” where used generically includes alkyl, aryl, cycloalkyl,aralkyl and alkaryl groups. Where any reference herein is made to anypatent, patent application or publication, the teachings are herebyincorporated by reference herein.

[0020] The hydrolysis and condensation reactions are suitably performedin a diluent comprising a mixture of one or more organic acids and oneor more inorganic halides at a temperature from 0 to 200° C., preferably50-150° C. A preferred organic acid is acetic acid. A preferred acidmixture is a combination of glacial acetic acid and concentratedhydrochloric acid, most preferably in a volume of 10/1 to 1/1.Preferably the metal is finely comminuted, uniformly dispersed in theacid mixture, and used in approximately an equimolar ratio with theketoester. The ketone product is suitably recovered by adding themixture to water, cooling and recovering the product by separation fromthe aqueous mixture.

[0021] The reduction of the ketone can be accomplished using sodiumborohydride or similar reducing agent in a solvent or diluent at atemperature from 0 to 150° C., followed by quenching with an acid. Asuitable diluent mixture is a chloroform/ethanol mixture, preferably ina volume ratio from 10/50 to 90/10, most preferably about 50/10. Thefinal steps of substitution and elimination may be conducted attemperatures from 0 to 150° C. using multiple steps or combining theseparate steps. The initial substitution is desirable conducted in thepresence of an acid acceptor such as pyridine. Highly desirably, thehydroxyl group is first converted to a sulfonic acid ester by reactionwith, methanesulfonyl chloride which is readily converted to the halideby reaction with a metal halide such as lithium bromide. The foregoingsteps are desirably conducted in the presence of an organic solvent,such as methylenechloride for the first step and acetone for the secondstep. The final step in formation of the cyclopentadiene orcyclopentadienyl ligand uses standard organometallic techniques,generally metalization or similar metathesis reactions depending on thedesired final product. The skilled artisan will appreciate that thefinal step of elimination (or deprotonation) may be combined with afunctionalizing step if desired. When the preferred combination ofelimination/deprotonation, and replacement operations are performed inone step, two or more equivalents of a base, preferably from 2 to 2.5equivalents, are used to cause both elimination and deprotonation, andthe functionalizing reagent, R⁷Fs is added after the deprotonation stepis completed or substantially completed. A preferred functionalizingreagent is R⁷-Z′Y—H.

[0022] The present process has proven to be highly desirable in theformation of certain bulky multiring cyclopentadiene derivatives,specifically 1H-cyclopenta(l)phenanthrene derivatives. Especiallydesirable is its use in a process for forming2,3-dihydro-2-oxo-1H-cyclopenta(l)phenanthrene by reaction of an alkyl3,3a-dihydro-3a-hydroxy-2-oxo-2H-cyclopenta(l)phenanthrene-1-carboxylate. This may be illustrated schematically asfollows:

[0023] wherein R is as previously defined.

[0024] In the subsequent steps, the ketone is converted to a2,3-dihydro-2-substituted-(1H)cyclopenta(l)phenanthrene ligand, asfollows:

[0025] wherein Lg is as previously defined.

[0026] In the final steps, the2,3-dihydro-2′-substituted-1H-cyclopenta(l)phenanthrene compound may beconverted to the desired ligand group for further synthesis usingstandard metalizing and substitution procedures.

[0027] Alkyl3,3a-dihydro-3a-hydroxy-2-oxo-2H-cyclopenta(l)phenanthrene-1-carboxylatecompounds for use in the foregoing procedure are prepared according toknown techniques. One suitable technique is condensation of9,10-phenanthrene quinone with an alkyl acetoacetate, such as methylacetoacetate or ethyl acetoacetate, in the presence of an acid acceptorsuch as piperidine. The initial 9,10-phenanthrene quinone, if notavailable commercially, may be readily prepared by reaction ofphenanthrene with excess acetic acid in the presence of an oxidizingagent such as potassium bromate. The foregoing synthetic procedures areillustrated as follows:

[0028] wherein R is as previously defined.

[0029] As previously mentioned, the foregoing syntheses are useful inpreparing ligands for metal complexes that are components of additionpolymerization catalyst compositions. Preferred metal complexesgenerally correspond to the formula: CpZMX_(x)L_(I)X′_(x′)(IA);

[0030] where Cp is a cyclopentadienyl ligand derived from the foregoingcyclopentadienyl or substituted cyclopentadienyl compounds;

[0031] M is titanium, zirconium or hafnium in the +2, +3 or +4 formaloxidation state;

[0032] Z is either a cyclic or noncyclic ligand group containingdelocalized π-electrons, including a second cyclopentadienyl ring systemgroup as herein previously disclosed for Cp, said Z being bonded to M bymeans of delocalized π-electrons and optionally covalently bonded to Cpthrough a divalent bridging group, or Z is a divalent moiety lacking indelocalized π-electrons that is covalently bonded to Cp and M, or such amoiety comprising one σ-bond by which it is bonded to Cp, and a neutraltwo electron pair able to form a coordinate-covalent bond to M, said Zcomprising boron, or a member of Group 14 of the Periodic Table of theElements, and also comprising nitrogen, phosphorus, sulfur or oxygen;

[0033] X is a monovalent anionic ligand group having up to 60 atomsother than hydrogen;

[0034] L independently each occurrence is a neutral ligand having up to20 atoms;

[0035] X′ is a divalent anionic ligand group having up to 60 atoms;

[0036] x is 0, 1, 2, or 3;

[0037] I is a number from 0 to 2, and

[0038] x′ is 0 or 1.

[0039] The above complexes may exist as isolated crystals optionally inpure form, or as a mixture with other complexes, in the form of asolvated adduct, optionally in a solvent, especially an organic liquid,as well as in the form of a dimer or chelated derivative thereof,wherein the chelating agent is an organic material such asethylenediaminetetraacetic acid (EDTA).

[0040] The catalyst compositions for olefin polymerization generallycomprise:

[0041] A. 1) a metal complex of formula (IA), and 2) an activatingcocatalyst, the molar ratio of 1) to 2) being from 1:10,000 to 100:1, or

[0042] B. the reaction product formed by converting a metal complex offormula (IA) to an active catalyst by use of an activating technique.

[0043] The olefin polymerization processes generally comprise contactingone or more C₂₋₂₀ α-olefins under polymerization conditions with acatalyst comprising:

[0044] A. 1) a metal complex of formula (IA), and 2) an activatingcocatalyst, the molar ratio of 1) to 2) being from 1:10,000 to 100:1, or

[0045] B. the reaction product formed by converting a metal complex offormula (IA) to an active catalyst by use of an activating technique.

[0046] The catalyst compositions may also be supported on a supportmaterial and used in olefin polymerization processes in a slurry or inthe gas phase. The catalyst may be prepolymerized with one or moreolefin monomers in situ in a polymerization reactor or in a separateprocess with intermediate recovery of the prepolymerized catalyst priorto the primary polymerization process.

[0047] Highly preferred metal complexes prepared by using thecyclopentadiene compounds prepared by the present process correspond tothe formula:

[0048] where M is titanium, zirconium or hafnium in the +2, +3 or +4formal oxidation state;

[0049] R¹ independently each occurrence is hydrogen, hydrocarbyl, silyl,germyl, halide, hydrocarbyloxy, hydrocarbylsiloxy,hydrocarbylsilylamino, di(hydrocarbyl)amino, hydrocarbyleneamino,di(hydrocarbyl)phosphino, hydrocarbylene-phosphino, hydrocarbylsulfido,halo- substituted hydrocarbyl, hydrocarbyloxy- substituted hydrocarbyl,silyl- substituted hydrocarbyl, hydrocarbylsiloxy- substitutedhydrocarbyl, hydrocarbylsilylamino- substituted hydrocarbyl,di(hydrocarbyl)amino- substituted hydrocarbyl,hydrocarbyleneamino-substituted hydrocarbyl, di(hydrocarbyl)phosphino-substituted hydrocarbyl, hydrocarbylenephosphino- substitutedhydrocarbyl, or hydrocarbylsulfido- substituted hydrocarbyl, said R¹group having up to 40 atoms not counting hydrogen atoms, and optionallytwo or more of the foregoing adjacent R¹ groups may together form adivalent derivative thereby forming a saturated or unsaturated fusedring, and further optionally one or more of the carbons of any of therings may be replaced by a nitrogen or sulfur atom;

[0050] Z is a divalent moiety lacking in delocalized π-electrons, orsuch a moiety comprising one σ-bond and a neutral two electron pair ableto form a coordinate-covalent bond to M, said Z comprising boron, or amember of Group 14 of the Periodic Table of the Elements, and alsocomprising nitrogen, phosphorus, sulfur or oxygen;

[0051] X is a monovalent anionic ligand group having up to 60 atomsexclusive of the class of ligands that are cyclic ligand groups bound toM through delocalized π-electrons;

[0052] L independently each occurrence is a neutral ligating compoundhaving up to 20 atoms;

[0053] X′ is a divalent anionic ligand group having up to 60 atoms;

[0054] x is 0, 1, 2, or 3;

[0055] I is a number from 0 to 2, and

[0056] x′ is 0 or 1.

[0057] In the metal complexes, preferred L groups are carbon monoxide;phosphines, especially trimethylphosphine, triethylphosphine,triphenylphosphine and bis(1,2-dimethylphosphino)ethane; P(OR⁴)₃,wherein R⁴ is C₁₋₂₀ hydrocarbyl; ethers, especially tetrahydrofuran;amines, especially pyridine, bipyridine, tetramethylethylenediamine(TMEDA), and triethylamine; olefins; and neutral conjugated dieneshaving from 4 to 40, preferably 5 to 40 carbon atoms. Complexesincluding such neutral diene L groups are those wherein the metal is inthe +2 formal oxidation state.

[0058] Further in reference to the metal complexes, X preferably isselected from the group consisting of hydro, halo, hydrocarbyl, silyl,and N,N-dialkylamino- substituted hydrocarbyl. The number of X groupsdepends on the oxidation state of M, whether Z is divalent or not andwhether any neutral diene groups or divalent X′ groups are present. Theskilled artisan will appreciate that the quantity of the varioussubstituents and the identity of Z are chosen to provide charge balance,thereby resulting in a neutral metal complex. For example, when Z isdivalent, and x is zero, x′ is two less than the formal oxidation stateof M. When Z contains one neutral two electron coordinate-covalentbonding site, and M is in a formal oxidation state of +3, x may equalzero and x′ equal 1, or x may equal 2 and x′ equal zero. In a finalexample, if M is in a formal oxidation state of +2, Z may be a divalentligand group, whereupon x and x′ are both equal to zero and one neutralL ligand group may be present.

[0059] The complexes can be prepared by combining a Group 4 metaltetrahalide or tetraamide salt with the corresponding cyclopentadienylring system ligand dianion in an inert diluent. Optionally a reducingagent can be employed to produce the lower oxidation state complexes,and standard ligand exchange procedures can by used to produce differentligand substituents.

[0060] Processes that are suitably adapted for use herein are well knownto synthetic organometallic chemists. The synthesis of thecyclopentadiene compounds, derivatives thereof, and metal complexes, andall other preparations herein, unless stated to the contrary, areconducted in a suitable noninterfering solvent at a temperature from−100 to 300° C., preferably from −80 to 150° C., most preferably from 0to 50° C. By the term “reducing agent” herein is meant a metal orcompound which, under reducing conditions causes the metal M, to bereduced from a higher to a lower oxidation state, or for organicsyntheses, causes addition of hydrogen to the compound. Examples ofsuitable metal reducing agents are alkali metals, alkaline earth metals,aluminum and zinc, alloys of alkali metals or alkaline earth metals suchas sodium/mercury amalgam and sodium/potassium alloy. Examples ofsuitable reducing agent compounds are sodium naphthalenide, potassiumgraphite, lithium alkyls, lithium or potassium alkadienyls; and Grignardreagents. Most preferred reducing agents are the alkali metals oralkaline earth metals, especially lithium and magnesium metal. By theterm “oxidizing agent” herein is meant a metal or compound which causesthe metal M, to be oxidized from a lower to a higher oxidation state, orfor organic syntheses, causes addition of oxygen to the compound.Suitable oxidizing agents for organometallic oxidations includechlorinated hydrocarbons, especially methylenechloride. Suitableoxidizing agents for organic syntheses include potassium bromate.

[0061] Suitable reaction media for the formation of the complexesinclude aliphatic and aromatic hydrocarbons, ethers, and cyclic ethers,particularly branched-chain hydrocarbons such as isobutane, butane,pentane, hexane, heptane, octane, and mixtures thereof; cyclic andalicyclic hydrocarbons such as cyclohexane, cycloheptane,methylcyclohexane, methylcycloheptane, and mixtures thereof; aromaticand hydrocarbyl-substituted aromatic compounds such as benzene, toluene,and xylene, C₁₋₄ dialkyl ethers, C₁₋₄ dialkyl ether derivatives of(poly)alkylene glycols, and tetrahydrofuran. Mixtures of the foregoingare also suitable. All of the foregoing steps are conducted according towell known organic or organometallic synthetic techniques.

[0062] The complexes are rendered catalytically active by combinationwith an activating cocatalyst or by use of an activating technique.Suitable activating cocatalysts for use herein include polymeric oroligomeric alumoxanes, especially methylalumoxane, triisobutyl aluminummodified methylalumoxane, or isobutylalumoxane; neutral Lewis acids,such as C₁₋₃₀ hydrocarbyl substituted Group 13 compounds, especiallytri(hydrocarbyl)aluminum- or tri(hydrocarbyl)boron compounds andhalogenated (including perhalogenated) derivatives thereof, having from1 to 10 carbons in each hydrocarbyl or halogenated hydrocarbyl group,more especially perfluorinated tri(aryl)boron compounds, and mostespecially tris(pentafluorophenyl)borane; nonpolymeric, compatible,noncoordinating, ion forming compounds (including the use of suchcompounds under oxidizing conditions), especially the use of ammonium-,phosphonium-, oxonium-, carbonium-, silylium- or sulfonium- salts ofcompatible, noncoordinating anions, or ferrocenium salts of compatible,noncoordinating anions; bulk electrolysis (explained in more detailhereinafter); and combinations of the foregoing activating cocatalystsand techniques. The foregoing activating cocatalysts and activatingtechniques have been previously taught with respect to different metalcomplexes in the following references: U.S. Pat. Nos. 5,153,157,5,064,802, 5,321,106, 5,350,723, and EP-A-520,732 (equivalent to U.S.Ser. No. 07/876,268), the teachings of which are hereby incorporated byreference.

[0063] Combinations of neutral Lewis acids, especially the combinationof a trialkyl aluminum compound having from 1 to 4 carbons in each alkylgroup and a halogenated tri(hydrocarbyl)boron compound having from 1 to20 carbons in each hydrocarbyl group, especiallytris(pentafluorophenyl)borane, further combinations of such neutralLewis acid mixtures with a polymeric or oligomeric alumoxane, andcombinations of a single neutral Lewis acid, especiallytris(pentafluorophenyl)borane with a polymeric or oligomeric alumoxaneare especially desirable activating cocatalysts. Preferred molar ratiosof Group 4 metal complex:tris(pentafluorophenyl-borane:alumoxane arefrom 1:1:1 to 1:5:20, more preferably from 1:1:1.5 to 1:5:10.

[0064] Suitable ion forming compounds useful as cocatalysts in oneembodiment of the present invention comprise a cation which is aBronsted acid capable of donating a proton, and a compatible,noncoordinating anion, A⁻. As used herein, the term “noncoordinating”means an anion or substance which either does not coordinate to theGroup 4 metal containing precursor complex and the catalytic derivativederived therefrom, or which is only weakly coordinated to such complexesthereby remaining sufficiently labile to be displaced by a neutral Lewisbase. A noncoordinating anion specifically refers to an anion which whenfunctioning as a charge balancing anion in a cationic metal complex doesnot transfer an anionic substituent or fragment thereof to said cationthereby forming neutral complexes. “Compatible anions” are anions whichare not degraded to neutrality when the initially formed complexdecomposes and are noninterfering with desired subsequent polymerizationor other uses of the complex.

[0065] Preferred anions are those containing a single coordinationcomplex comprising a charge-bearing metal or metalloid core which anionis capable of balancing the charge of the active catalyst species (themetal cation) which may be formed when the two components are combined.Also, said anion should be sufficiently labile to be displaced byolefinic, diolefinic and acetylenically unsaturated compounds or otherneutral Lewis bases such as ethers or nitrites. Suitable metals include,but are not limited to, aluminum, gold and platinum. Suitable metalloidsinclude, but are not limited to, boron, phosphorus, and silicon.Compounds containing anions which comprise coordination complexescontaining a single metal or metalloid atom are, of course, well knownand many, particularly such compounds containing a single boron atom inthe anion portion, are available commercially.

[0066] Preferably such cocatalysts may be represented by the followinggeneral formula:

(L*−H)⁺(A)⁻

[0067] wherein:

[0068] L* is a neutral Lewis base;

[0069] (L*−H)⁺ is a conjugate Bronsted acid of L*; and

[0070] A⁻ is a noncoordinating, compatible anion having a charge of −1.

[0071] More preferably A⁻ corresponds to the formula: [M′Q₄]⁻;

[0072] wherein:

[0073] M′ is boron or aluminum in the +3 formal oxidation state; and

[0074] Q independently each occurrence is selected from hydride,dialkylamido, halide, hydrocarbyl, hydrocarbyloxide,halosubstituted-hydrocarbyl, halosubstituted hydrocarbyloxy, and halo-substituted silylhydrocarbyl radicals (including perhalogenatedhydrocarbyl- perhalogenated hydrocarbyloxy- and perhalogenatedsilylhydrocarbyl radicals), said Q having up to 20 carbons with theproviso that in not more than one occurrence is Q halide. Examples ofsuitable hydrocarbyloxide Q groups are disclosed in U.S. Pat. No.5,296,433, the teachings of which are herein incorporated by reference.

[0075] Activating cocatalysts comprising boron which are particularlyuseful in the preparation of catalyst compositions may be represented bythe following general formula:

(L*−H)⁺(BQ₄)⁻;

[0076] wherein:

[0077] L* is as previously defined;

[0078] B is boron in a formal oxidation state of 3; and

[0079] Q is a hydrocarbyl-, hydrocarbyloxy-, fluorinated hydrocarbyl-,fluorinated hydrocarbyloxy-, or fluorinated silylhydrocarbyl- group ofup to 20 nonhydrogen atoms, with the proviso that in not more than oneoccasion is 0 hydrocarbyl.

[0080] Preferred Lewis base salts are ammonium salts, more preferablytrialkylammonium salts containing one or more C₁₂₋₄₀ alkyl groups, mostpreferably methyldioctadecylammonium or dimethyloctadecylammonium salts.Most preferably, Q is each occurrence an inertly substituted aryl group,especially, a pentafluorophenyl or p-dialkylaluminoxyphenyl.

EXAMPLES

[0081] The skilled artisan will appreciate that the invention disclosedherein may be practiced in the absence of any component which has notbeen specifically disclosed. The following examples are provided asfurther illustration of the invention and are not to be construed aslimiting. Unless stated to the contrary all parts and percentages areexpressed on a weight basis. All syntheses of air or water sensitivecompounds were performed under dry nitrogen or argon atmosphere using acombination of glove box and high vacuum techniques. Solvents werepurified by passing through double columns charged with activatedalumina and a purification catalyst (Q-® catalyst available fromEnglehardt Corporation). The term “overnight”, if used, refers to a timeof approximately 16-18 hours, “room temperature”, if used, refers to atemperature of about 20-25° C., and “mixed alkanes” refers to a mixtureof mostly C₆-C₁₂ alkanes available commercially under the trademarkIsopar E™ from Exxon Chemicals Inc.

Example 1 Synthesis of 2,3-dihydro-2-oxo-1H-cyclopenta(l)phenanthrene

[0082] (1) Preparation of Phenanthrenequinone:

[0083] Phenanthrene (16 g , Aldrich Tech Grade (90 percent), 0.081 mol)and acetic acid (200 ml) were stirred and heated to 70-75° C. Potassiumbromate (32 g, 0.19 mol) was added in 2 portions. After the addition ofthe first portion the temperature rose to reflux with evolution ofbromine vapors. The second portion was added and the condenser wasreplaced by a distillation head. The heating was continued untill thedistillate was colorless. The deep red solution was cooled and pouredinto water (300 ml) and the precipitate was isolated by filtration. Thecrude product was purified by reslurrying in 100 ml of hot (70° C.)aqueous sodium bisulfite solution (40 percent) and filtering while hot.The deep red filtrate was cooled and treated with aqueous sodiumcarbonate untill basic. The precipitated product was recovered byextraction with methylene chloride, dried and concentrated to yield 13.4g (80 percent yield) of orange yellow solid : mp 182-184° C.

[0084] (2) Preparation of2,11b-dihydro-11b-hydroxy-2-oxo-1H-cyclopenta[l]phenanthrene-3-carboxylicacid methyl ester.

[0085] A slurry of phenanthrenequinone (10.5 g, 0.05 mol) in ethanol (60ml) containing methyl acetoacetate (6.96 g, 0.06 mol) and piperidine(6-8 drops) was refluxed for 2 to 2.5 h. The quinone eventuallydissolved and the entire reaction mixture solidified. Filtration of thecooled mixture gave 14.3 g (93 percent) of a white solid: ¹H NMR(CDCl₃,δ) 3.21 (d of d, 2H, J=18 Hz), 3.87 (s, 3H), 7.3-8.0 (m, 8H).

[0086] (3) Preparation of 1,3-Dihydro-2H-Cyclopenta[l]phenanthrene-2-one

[0087] The ketoester of step 2 (14.1 g, 0.046 mol) was added to amixture of acetic acid (150 ml) and hydrochloric acid (5 ml) containingzinc dust (6 g, 0.092 mol). The mixture immediately solidified. Themixture was slowly heated to reflux when all the solids dissolved givinga clear yellow solution containing unreacted zinc granules. The mixturewas refluxed for 4 h and filtered while hot. The filtrate was cooled andpoured into ice water. The resulting white precipitate was filtered anddried. A small amount of the product that had crystallized out duringthe hot filtration was recovered by extraction with methylene chlorideand concentrating to yield the product. The combined yield was 10.4 g(97.3 percent). ¹H NMR (CDCl₃,δ) 3.71 (s, 4H), 7.62 (bs, 6H), 8.68 (d,2H, J=7 Hz).

[0088] (4) Preparation of 2,3-Dihydro-1H-Cyclopenta[l]phenanthrene-2-ol

[0089] Sodium borohydride (1 g, 0.027 mol) was added to a slurry of2,3-Dihydro-2H-Cyclopenta[l]phenanthrene-2-one (4.6 g, 0.02 mol) in 50ml of chloroform and 10 ml of ethanol. The resulting yellow solution wasstirred overnight and quenched with 10 percent aqueous HCl. The mixturewas transfered to a separatory funnel and the organic layer was washedwith saturated sodium bicarbonate solution, dried over anhydrousmagnesium sulfate and concentrated under reduced pressure to yield theproduct as a yellowish white solid. Yield was 4.7 g, 100 percent). ¹HNMR (CDCl₃-DMSO-d₆, δ) 3.31 (d, 2H, J=16 Hz), 3.56 (d of d, 2H, J=16, 6Hz), 4.76 (brs, 1H), 4.91 (brs, 1H), 7.59-7.85 (m, 6H), 8.67-8.70 (m,2H).

[0090] (5) Preparation of 2,3-Dihydro-1H-Cyclopenta[l]phenanthrene-2-olmethanesulfonate

[0091] To a stirred suspension of2,3-dihydro-1H-cyclopentaphenanthrene-2-ol (2.34 g, 0.01 mol) in 20 mlof pyridine was added a solution of methanesulfonyl chloride (2.28 g,0.02 mol) in 15 ml of methylene chloride and allowed to stir a for 2 hrat room temperature. The reaction mixture was worked up by washing with10 percent aqueous HCl, drying over anhydrous magnesium sulfate andconcentrating under reduced pressure to yield the methanesulfonate as atan solid (3.11 g, 100 percent). ¹H NMR (CDCl₃, δ) 3.05 (s, 3H),3.58-3.69 (m, 4H), 5.75 (m, 1H), 7.60-7.76 (m, 6H), 8.68 (m, 2H).

[0092] (6) Preparation of2-Bromo-2,3-Dihydro-1H-Cyclopenta[l]phenanthrene

[0093] A mixture of 2,3-Dihydro-1H-Cyclopenta[l]phenanthrene-2-olmethanesulfonate (3.11 g, 0.01 mol) and lithium bromide(2.61 g, 0.03mol) in 50 ml of acetone was refluxed for 18 hr. The reaction mixturewas worked up by concentrating to remove the volatiles and extractingwith a mixture of methylene chloride and hexane(1:3) and filteringthrough silica gel to yield 2.34 g (80 percent) of the bromide as a buffcolored solid. ¹H NMR (CDCl₃, δ) 3.73-3.94 (m, 4H), 4.97 (m, 1H),7.58-7.76 (m, 6H), 8.66 (m, 2H); ¹³C NMR (CDCl₃, δ) 44.34, 47.28,123.20, 124.69, 126.07, 126.83, 129.17, 130.38, 134.40.

[0094] (7) Preparation of(1H-Cyclopenta[l]phenanthrene-2-yl)dimethyl(t-butylamino)silane

[0095] To a solution of 2-bromo-cyclopentaphenanthrene (0.500 g, 1.68mmol) in 40 mL THF was added 25 percent (wt/wt) potassium amylate incyclohexane (2.0 g, 3.7 mmol). The solution color changed to orangeimmediately and a precipitate formed. The mixture was heated to reflux.After 30 minutes heating the mixture was cooled and the volatilematerials were removed under reduced pressure. The residue was slurriedin 30 mL THF and this mixture was added slowly to neatdichlorodimethylsilane (2.0 mL, 17 mmol). The resulting mixture was paleyellow. Fifteen minutes after the addition was complete, volatilematerials were removed under reduced pressure. The residue was slurriedin 30 mL THF and tert-butylamine was added to the resulting mixturewhich was left to stir overnight. The volatile materials were removedunder reduced pressure and the resulting residue was extracted threetimes with a total of 60 mL of mixed hexanes. The extracts were filteredand volatile materials were removed from the combined filtrates underreduced pressure. The product was formed as white crystals upon cooling.Yield of the desired product was 0.575 g, 99 percent.

Example 2 Preparation of 1,3-Dihydro-2H-Cyclopenta[l]phenanthrene-2-one

[0096] An alternate preparation of1,3-dihydro-2H-cyclopenta[l]phenanthrene-2-one (step 3) using zincdichloride started with 3.2 g, (0.01 mol) of2,11b-dihydro-11b-hydroxy-2-oxo-1H-cyclopenta[l]phenanthrene-3-carboxylicacid ethyl ester. The ketoester (3.2 g, 0.01 mol) was added to a mixtureof acetic acid (100 ml) containing zinc dust (6 g, 0.092 mol) and zincdichloride (2.72 g, 0.02 mol). The mixture was refluxed for 4 h andfiltered while hot. The filtrate was cooled and the resulting whiteprecipitate was recovered by filtration and dried. Yield was 1.56 g (67percent).

1. A process for forming a 4-ketocyclopentene compound comprisingreducing a 1-carbohydrocarbyloxy-2-keto-4-hydroxy-5-cyclopentenecompound by contacting with a metal and decarboxylating the resultingreaction product by contacting with a mixture of an organic acid and aninorganic halide compound selected from the group consisting of zincdichloride and zinc dibromide.
 2. The process of claim 1 wherein themetal is zinc, the organic acid is acetic acid, and the1-carbohydrocarbyloxy-2-keto-4-hydroxy-5-cyclopentene and4-ketocyclopentene compounds correspond to the formula:

wherein, R is C₁₋₂₀ hydrocarbyl; and R¹ independently each occurrence ishydrogen, hydrocarbyl, silyl, germyl, halide, or halo- substitutedhydrocarbyl, said R¹ group having up to 40 atoms not counting hydrogenatoms, and optionally two or more of the foregoing adjacent R¹ groupsmay together form a divalent derivative thereby forming a saturated orunsaturated fused ring or multiple ring system, and further optionallyone or more of the carbons of R¹ in any of the so formed rings may bereplaced by a nitrogen, boron, phosphorus or sulfur atom.
 3. The processof claim 1 wherein 2,3-dihydro-2-oxo-1H-cyclopenta(l)phenanthrene isprepared from a C₁₋₂₀ alkyl3,3a-dihydro-3a-hydroxy-2-oxo-2H-cyclopenta(l)phenanthrene-1-carboxylate.4. A process for preparing a cyclopententadiene or substitutedcyclopentadiene compound, the steps of the process comprising reducing aketone to form an alcohol, replacing the hydroxyl functionality of thealcohol under substitution conditions with a leaving group, anddeprotonating the resulting product under base induced eliminationconditions to form the cyclopentadiene compound, wherein the ketone,alcohol, substituted product and cyclopentadiene correspond to thefollowing formulas, and the process corresponds to the following scheme:

wherein: R¹ independently each occurrence is hydrogen, hydrocarbyl,silyl, germyl, halide, or halo- substituted hydrocarbyl, said R¹ grouphaving up to 40 atoms not counting hydrogen atoms, and optionally two ormore of the foregoing adjacent R¹ groups may together form a divalentderivative thereby forming a saturated or unsaturated fused ring ormultiple ring system, and further optionally one or more of the carbonsof R¹ in any of the so formed rings may be replaced by a nitrogen,boron, phosphorus or sulfur atom; Lg is a suitable ligand group that issubject to base induced elimination, and the ketone is preparedaccording to the process of claim
 1. 5. A process for preparing afunctionalized cyclopentadienyl compound by reducing a ketone to form analcohol, replacing the hydroxyl functionality of the alcohol undersubstitution conditions with a leaving group, and reacting the leavinggroup substituted cyclopentene compound with at least two equivalents ofa base and a source of a functionalizing ligand, said process comprisingin combination a reduction, substitution, elimination, deprotonation andreplacement operation illustrated schematically as follows:

wherein, the ketone is prepared according to the process of claim 1; R¹independently each occurrence is hydrogen, hydrocarbyl, silyl, germyl,halide, or halo- substituted hydrocarbyl, said R¹ group having up to 40atoms not counting hydrogen atoms, and optionally two or more of theforegoing adjacent R¹ groups may together form a divalent derivativethereby forming a saturated or unsaturated fused ring or multiple ringsystem, and further optionally one or more of the carbons of R¹ in anyof the so formed rings may be replaced by a nitrogen, boron, phosphorusor sulfur atom; Lg is a suitable ligand group that is subject to baseinduced elimination, R⁷ is a leaving group,

Fs is -Z′YH, -Z′Y′, or wherein Y is —O—, —S—, —NR⁵—, or —PR⁵—, Y′ is—NR⁵ ₂, or —PR⁵ ₂; Z′ is SiR⁵ ₂, CR⁵ ₂, SiR⁵ ₂SiR⁵ ₂, CR⁵ ₂CR⁵ ₂,CR⁵═CR⁵, CR⁵ ₂SiR⁵ ₂, BR⁵, B═NR⁵ ₂, or GeR⁵ ₂; and R⁵ each occurrence isindependently hydrogen, or a member selected from hydrocarbyl,hydrocarbyloxy, silyl, halogenated alkyl, halogenated aryl, andcombinations thereof, said R⁵ having up to 20 non-hydrogen atoms, andoptionally, two R⁵ groups from Z′ (when R⁵ is not hydrogen), or an R⁵group from Z′ and an R⁵ group from Y form a ring system.